jenes.population

Class Pool<T extends Chromosome>

java.lang.Object

jenes.population.Pool<T>

public class Pool<T extends Chromosome>
extends java.lang.Object

This class provides a pool of individuals to which Population can access to retrieve individuals. The pool is highly efficient when the algorithm the overall number of individuals and the lenght of their chromosome do not change along the algorithm evolution.

Since:

2.0

Version:

2.0

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Pool.Statistics This class provides some basic statistics regarding the Pool .

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_SIZE The default population size

Constructor Summary

Constructors

Constructor and Description
Pool() Constructs a new empty pool
Pool(int n) Constructs a new pool with a given number of (initially no genome) individuals
Pool(int n, Individual<T> sample) Constructs a new pool with a given number of individuals, clones of sample.

Method Summary

Methods

Modifier and Type	Method and Description
void	add(java.util.Collection<Individual<T>> individuals) Adds a collection of individuals to the pool.
void	assign(Individual<T> ind) Adds the individual given as argument to the list of assigned individuals.
int	availability() Returns the number of available individuals
void	clear() Removes all the individuals from this population.
Individual<T>	getIndividual() Returns an Individual from the set of available individuals.
Pool.Statistics	getStatistics() Returns a new instance of pool (@link Statistics).
void	release(Individual<T> ind) Removes the Individual, given as argument, from the list of assigned individuals and makes it available
void	remove(java.util.Collection<Individual<T>> individuals) Removes the collection of individuals given as argument from the list of available individuals and from the list of assigned individuals
void	resize() Performs an automic pool resizing.
void	setAvailability(int size) Resizes the pool.
int	size() Returns the pool size.
java.lang.String	toCompleteString() Returns a string complete pool representation.
java.lang.String	toString() Returns a string representation of this pool.
void	updateStatistics(Pool.Statistics stats) Updates pool statistics

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

DEFAULT_SIZE

public static final int DEFAULT_SIZE

The default population size

See Also:

Constant Field Values

Constructor Detail

Pool

public Pool()

Constructs a new empty pool

Pool

public Pool(int n)

Constructs a new pool with a given number of (initially no genome) individuals

Parameters:

n - - the initial number of individuals

Pool

public Pool(int n,
    Individual<T> sample)

Constructs a new pool with a given number of individuals, clones of sample.

Parameters:

n - - the initial number of individuals

sample - - the prototype individual

Method Detail

getIndividual

public final Individual<T> getIndividual()

Returns an Individual from the set of available individuals. If individuals are not available, a new individual is created

Returns:

an available individual

assign

public final void assign(Individual<T> ind)

Adds the individual given as argument to the list of assigned individuals. If individual population makes use of a different pool, the individual is discarded.

Parameters:

ind - to be assigned

release

public final void release(Individual<T> ind)

Removes the Individual, given as argument, from the list of assigned individuals and makes it available

Parameters:

ind - - individual to be released

setAvailability

public final void setAvailability(int size)

Resizes the pool. If the new size is larger, new individuals will be added cloning random individuals, thus requiring that at least one individual is held; on contrary individuals are randomly generated.

If the new size is smaller than the old size, individuals are randomly removed from the pool.

Parameters:

size - the pool new size

resize

public final void resize()

Performs an automic pool resizing.

clear

public final void clear()

Removes all the individuals from this population.

size

public final int size()

Returns the pool size.

Returns:

the number of individuals in the pool.

availability

public final int availability()

Returns the number of available individuals

Returns:

the number of available individuals

remove

public final void remove(java.util.Collection<Individual<T>> individuals)

Removes the collection of individuals given as argument from the list of available individuals and from the list of assigned individuals

Parameters:

individuals -

add

public final void add(java.util.Collection<Individual<T>> individuals)

Adds a collection of individuals to the pool. If the individual belongs to a population with a different pool, the individual is discarded.

Parameters:

individuals - to add

getStatistics

public final Pool.Statistics getStatistics()

Returns a new instance of pool (@link Statistics).

Returns:

pool statistics

updateStatistics

public final void updateStatistics(Pool.Statistics stats)

Updates pool statistics

Parameters:

stats - the stastistics to update

toCompleteString

public final java.lang.String toCompleteString()

Returns a string complete pool representation.

Returns:

a new String complete string representing this pool.

toString

public final java.lang.String toString()

Returns a string representation of this pool.

Overrides:

toString in class java.lang.Object

Returns:

a new String object representing this pool.